Supervisory thermal management system and method for engine system warm up and regeneraton

ABSTRACT

This disclosure provides a thermal management system and method that can recommend operational behavior to an operator of an engine system to optimize fuel economy over a period of time in which a components of the engine system is in a warm up and/or regeneration state. In one representative embodiment, the expected temperature change of the engine component at a later time is determined based on inefficient operation of the engine, such as a transmission down shift resulting in higher engine speed and lower engine torque, and the expected temperature change of the engine component resulting from operating the engine under current conditions or expected conditions at that later time is determined. A determination is made as to whether the inefficient engine operation is the optimal operation in view of fuel economy and a recommendation is generated for the operator based if optimal operation is determined.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of priority to Provisional PatentApplication No. 61/430,430 filed on Jan. 6, 2011, Provisional PatentApplication No. 61/431,290 filed on Jan. 10, 2011, and ProvisionalPatent Application No. 61/431,291 filed on Jan. 10, 2011, the entirecontents of each of these applications being hereby incorporated byreference.

FIELD OF THE INVENTION

The invention relates to thermal management for an internal combustionengine for increased or optimal fuel efficiency, and more particularly,to a system and method for advising and instructing an operator of anengine system to increase or optimize fuel economy.

BACKGROUND

Design of internal combustion engine systems involves developing thermalmanagement systems for controlling various subsystems of an internalcombustion engine system. One parameter of concern is vehicle fueleconomy, which can be influenced by the temperature of engine systemcomponents. These components can include the engine, transmission andother powertrain components, and exhaust aftertreatment systemscomponents, which generally operate more efficiently after achieving asufficient operating temperature after a warm up period.

Generally, efficiency peaks when the system component temperatures reacha particular point. A system that is either too cold or too warm willdemonstrate degraded efficiency as compared to a system in theneighborhood of the temperature “sweet spot.” Traditionally, enginesystems and other powertrain components are isolated in the treatment ofpowertrain warm up. Engine calibrations often provide for “coldcalibration” functioning that is primarily targeted at preventingmisfire and maintaining emissions control rather than addressing fueleconomy.

In aftertreatment systems, two stages of thermal management that oftencost the system from the standpoint of fuel consumption are selectivecatalytic reduction (SCR) warm-up and diesel particulate filter (DPF)regeneration. These two stages of aftertreatment system componentthermal management also aid to warm-up a diesel oxidation catalyst (DOC)to light-off temperature. At light-off temperature the diesel fuelpresent in the DOC will ignite, yielding an exothermic reaction with aconsequent increase in exhaust gas temperature.

Currently, engine systems and other powertrain components are isolatedin the treatment of aftertreatment system thermal management. Enginecalibrations often provide for “regeneration calibration” and “warm-upcalibration” for the aftertreatment system. For example, a “DOC warm-upcalibration” can include injecting late post fuel that combustsin-cylinder sufficiently late in the piston cycle to primarily produceheat and little or no torque.

SUMMARY

This disclosure provides system and method for thermally managing aninternal combustion engine system to increased or optimal fuelefficiency during engine system warm up or regeneration periods. Thesystem and method determine whether a temporary inefficient operation ofthe engine can result in increased optimized fuel economy. The systemand method generates a recommendation to operate the engine systeminefficiently, such as by down shifting to a lower transmission gear toincrease engine speed, if it is determined the inefficient operationwould result in better fuel economy.

In one aspect, a method determines a transmission gear shiftrecommendation based on optimization of overall fuel economy. The methodincludes receiving data indicative of at least one current vehicleoperating condition, where the operating condition data includes datarepresenting or signifying at least one of transmission out power andspeed, current gear number, transmission gearing set, current enginetemperature, current engine speed, current engine torque, and fueling.Data are received from engine fueling maps based on cold and warm-upconditions, an expected temperature change is determined based on atransmission down shift and higher engine speed in view of the operatingcondition data and the fueling maps, and an expected temperature changeis determined based on a transmission up shift and lower engine speed inview of the operating condition data and the fueling maps. Atransmission gear shift recommendation is determined in view of thedetermined expected temperature changes based on optimization of overallfuel economy.

In another aspect of the disclosure, a system is adapted to determine atransmission gear shift recommendation based on optimization of overallfuel economy, and includes a vehicle operating condition moduleincluding data indicative of at least one current vehicle operatingcondition, where the operating condition data includes data representingor signifying at least one of transmission out power and speed, currentgear number, transmission gearing set, current engine temperature,current engine speed, current engine torque, and fueling. The systemincludes an engine fueling map module having data from engine fuelingmaps based on cold and warm-up conditions, and an expected temperaturechange module including data based on a transmission down shift andhigher engine speed in view of the operating condition data and thefueling maps, and including data based on transmission up shift andlower engine speed in view of the operating condition data and thefueling maps. An optimization module contains a transmission gear shiftrecommendation in view of the determined expected temperature changesbased on optimization of overall fuel economy.

In yet another aspect of the disclosure, a method of managing vehicleengine/transmission systems assists in thermal management of an engineexhaust aftertreatment system. The method includes receiving dataindicative of at least one current vehicle operating condition, wherethe operating condition data includes data signifying at least one oftransmission out power and speed, current gear number, transmissiongearing set, current engine temperature, current engine speed, currentengine torque, and fueling. Data are received from engine fueling mapsbased on warm-up conditions, a target temperature is received. A firstexpected exhaust temperature is determined based on a transmission downshift and higher engine speed in view of the operating condition dataand the fueling maps, a second expected exhaust temperature isdetermined based on a transmission down shift and higher engine speedcoupled with fuel dosing, and a third expected exhaust temperature isdetermined based on fuel dosing and non-shifted transmission. The first,second and third expected exhaust temperatures are compared against thetarget temperature, and a transmission gear shift recommendation isprovided in view of the compared expected exhaust temperatures based onan optimization of overall fuel economy.

In still another aspect of the disclosure, a system is adapted to managevehicle engine/transmission systems to assist in thermal management ofan engine exhaust aftertreatment system. The system includes a vehicleoperating condition module including data indicative of at least onecurrent vehicle operating condition, where the operating condition dataincludes data signifying at least one of transmission out power andspeed, current gear number, transmission gearing set, current enginetemperature, current engine speed, current engine torque, and fueling.An engine fueling map module includes data from engine fueling mapsbased on warm-up conditions, and a target temperature module includes atarget temperature. An expected exhaust temperature module contains afirst expected exhaust temperature based on a transmission down shiftand higher engine speed in view of the operating condition data and thefueling maps, a second expected exhaust temperature based on atransmission down shift and higher engine speed coupled with fueldosing, and a third expected exhaust temperature based on fuel dosingand non-shifted transmission. A comparison module contains a comparisonof the first, second and third expected exhaust temperatures relative tothe target temperature. An optimization module contains a transmissiongear shift recommendation in view of the comparison of the expectedexhaust temperatures, where the recommendation is based on anoptimization of overall fuel economy.

A method of managing vehicle engine/transmission systems assists inthermal management of an engine aftertreatment DOC warm-up system. Themethod includes receiving data indicative of at least one currentvehicle operating condition, where the operating condition data includesdata signifying at least one of transmission out power and speed,current gear number, transmission gearing set, current enginetemperature, current engine speed, current engine torque, and fueling.The method further includes receiving data from engine fueling mapsbased on warm-up conditions, and receiving a target temperature relatedto DOC light-off. A first expected exhaust temperature is determinedbased on a transmission down shift and higher engine speed in view ofthe operating condition data and the fueling maps, a second expectedexhaust temperature is determined based on a transmission down shift andhigher engine speed coupled with late post fuel injection, and a thirdexpected exhaust temperature is determined based on late post fuelinjection and non-shifted transmission. The first, second and thirdexpected exhaust temperatures are compared against the targettemperature, a transmission gear shift recommendation is provided inview of the compared expected exhaust temperatures based on anoptimization of overall fuel economy.

A system adapted to manage vehicle engine/transmission systems assistsin thermal management of an engine aftertreatment DOC warm-up system.The system includes a vehicle operating condition module including dataindicative of at least one current vehicle operating condition, wherethe operating condition data includes data signifying at least one oftransmission out power and speed, current gear number, transmissiongearing set, current engine temperature, current engine speed, currentengine torque, and fueling. The system further includes an enginefueling map module including data from engine fueling maps based onwarm-up conditions, and a target temperature module including a targettemperature related to DOC light-off. An expected exhaust temperaturemodule contains a first expected exhaust temperature based on atransmission down shift and higher engine speed in view of the operatingcondition data and the fueling maps, a second expected exhausttemperature based on a transmission down shift and higher engine speedcoupled with late post fuel injection, and a third expected exhausttemperature based on late post fuel injection and non-shiftedtransmission. A comparison module contains a comparison of the first,second and third expected exhaust temperatures relative to the targettemperature. An optimization module contains a transmission gear shiftrecommendation in view of the comparison of the expected exhausttemperatures, where the recommendation is based on an optimization ofoverall fuel economy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an internal combustion engine control systemincluding a cycle efficiency management (CEM) module according to anexemplary embodiment.

FIG. 2 is a diagram of a network system layout including the CEM moduleshown in FIG. 1.

FIG. 3. is a diagram showing details of an exemplary thermal managementmodule of the CEM module shown in FIG. 2.

FIG. 4 is a diagram of an exemplary powertrain warm up module of thethermal management module shown in FIG. 3.

FIG. 5 is a diagram of a turbocharger and aftertreatment systemaccording to an exemplary embodiment.

FIG. 6 is a diagram of an exemplary SCR warm up/DPF regeneration moduleof the thermal management module of FIG. 3.

FIG. 7 is a process flow diagram of a DPF regeneration process using GPSaccording to an exemplary embodiment.

FIG. 8 is a diagram of an exemplary DOC warm up module of the thermalmanagement module shown in FIG. 3.

DETAILED DESCRIPTION

FIG. 1 shows a diagram of an engine system 1 according to an embodiment.Engine system 1 can be integrated into a vehicle (not shown), such as atruck or an automobile. The engine system 1 includes a powertrain system2 including an internal combustion engine 3 and transmission 4, anexhaust gas aftertreatment system 5, an electronic control module ECM)6, and a cycle efficiency management (CEM) module 7 that employs controlprocesses to furnish an operator of the vehicle with anticipated andcurrently desired vehicle operational behavior to optimize fuel economy.The components of engine system 1 communicate with the ECM or oneanother via a network 10, which can be, for example, a controller areanetwork (CAN).

The control processes of the CEM focus on powertrain and aftertreatmentsystem components, such as the engine 3, transmission 4, accessories,final drive, wheels, vehicle, a particulate filter (e.g., a DPF), a DOCand an SCR catalyst. The processes interface with the operator toprovide guidance as to appropriate vehicle speed/power targets andtransmission gear selection targets. The CEM module 7 can be useful inconditioning an operator to optimize behavior, and thus fuel economybased on certain performance criteria. In other words, the CEM module 7can perform a supervisory role in connection with vehicle operation andinstruct the vehicle operator with recommendations via an operatorinterface.

While not shown in FIG. 1, the powertrain also can include an energyconversion device, such as a turbocharger (e.g., a variable geometryturbocharger (VGT)), a high pressure fuel system including fuelinjectors for injecting fuel into cylinders of the engine and at leastone dosing injector or injector function for injecting fuel into theexhaust gas upstream from aftertreatment system components. Thepowertrain 2 of FIG. 1 operates in accordance with a requested or setengine speed command Speed_(cmd) and fuel rate command Fuel_(cmd). Thesecommands are provided to a set of static lookup tables in the ECM 6 todetermine a pre-calibrated reference value for each of engine out O₂,engine out λ, engine out NOx, and intake O₂ corresponding to a currentoperating point or mode defined by the Speed_(cmd) and Fuel_(cmd)commands while maintaining compliance with emissions requirements. TheECM provides signals corresponding to the lookup table output to the tothe engine system components, such as the air handling systemcomponents, EGR valve, fuel system components to control the enginespeed and fueling. The term “pre-calibrated” is used herein to describea predetermined value derived by experiment and/or calculation andrepresents a baseline value corresponding to a requested engine speedand fueling requirement. A pre-calibrated value is sometimes referred toherein as a “normal” or “nominal” value that is predetermined and storedin memory and accessible by the engine system ECM (or other enginesystem controller).

One aspect of the CEM module 7 is to perform thermal management of theengine system 1 during warm up or regeneration periods by optimizingoperating temperatures during these periods by managing the temperatureof key powertrain components. The CEM module performs a supervisoryfunction by determining whether down-shifting, no-shifting orup-shifting the transmission from its current gear will yield a morefuel efficient solution in the long run. By down-shifting thetransmission, the engine operates at a higher speed while producing thesame amount of driveshaft power. The higher engine speed in thedown-shifted mode may place the engine at an operating point of lowerefficiency. This lower efficiency will cause more fuel to be used inproducing the same amount of power. This excess fuel energy will gotoward generating heat that will cause an increase in the systemtemperature. In contrast, the same concept can be used to create anup-shift event to potentially place the engine at a more efficientoperating condition, thereby reducing the amount of fuel energy used ingenerating heat. Thus, by shifting the transmission up or down, thesystem operating temperature of the engine system 1 can be controlled.

FIG. 2 shows a diagram a network system 15 of the monitoring and controlsystem according to an embodiment. The network system 15 includes theECM 6 and CEM module 7 shown in FIG. 1, and additional modules thatcommunicate with the ECM 6 and/or CEM module 7 via network 10 (e.g., aCAN). Generally, these additional modules can include an engineparameter/operating conditions module 20 that receives predeterminedvehicle parameters and current vehicle operating conditions, a roadterrain and routing module 30 that receives and/or stores terrainprofile data/information and routing information(destination/multidestination routing), and an operator interface modulethat receives operator input and provides output to the operator cancommunicate with the CEM module 7 via communications module 50 (e.g., aCAN network module) to provide information to the thermal managementmodule 60 of the CEM module 7. The communications module can include aGPS unit 52 to receive information to determine coordinate positioningand/or supply data in advance of an operation or forthcoming positionsor in real-time as the vehicle is operated and route traversed.Alternate embodiments provide for road terrain data to be maintained incomputer storage and downloaded to the CEM module prior to the start ofa trip or transmitted wirelessly over-the-air at any time, for example,by using cellular technology. The positioning information provided bythe GPS unit 52 can be used by the operator interface module 40 todetermine and where the vehicle is on a route, the current roadconditions, and to predict future road conditions and related enginespeed and fueling requirements.

The CEM module 6 can receive information from the ECM 5, the engineparameter/operating conditions module 20, the road terrain module 30,and/or the operator interface module 40 via the communications module50, and then this information can be used by the thermal managementmodule 60 to determine whether to recommended changing to or maintaininga low efficiency operation, for example, by recommending, to theoperator via the operator interface module to increase the engine speedvia a down shift operation. Additionally, the thermal management modulecan calculate the cost economy benefit realizable by the recommendedoperation and output this information to the operator interface module40 for display to the operator or communication this information to aremote site. It is to be appreciated that other forms of the costbenefit information can be provided by the thermal management module,such as cost benefit accumulated over a period of time, histories ofoperator input and/or adherence to recommendations to the operatorinterface module 40, the communications module 50. This information canbe stored in local memory of the ECM 6, the CEM module 7, or another oneof the modules not shown), in tangible memory separate from the modulesor distributed in memory across plural modules (not shown), or in memoryremote from the after being transmitted via communication module 40 ordownloaded via another process. This information can be readilyaccessible by the operator via manipulating an interface such as a menudriven touch screen or other output device.

FIG. 3 is a diagram showing more details of an exemplary thermalmanagement module 60. As shown in FIG. 3, the thermal management moduleincludes the powertrain module 100, an SCR warm up/DPF regenerationmodule 200, and a DOC warm up module 300. The thermal management module60 is provided with inputs that include information relating to currentpower and speed of the powertrain components, information relating tothe powertrain equipment available and currently used, the currenttemperature of at least one powertrain component, and prescribed fuelingdata. The submodules of the thermal management module 60 use subsets ofthe inputs information to determine whether temporary inefficientoperation of the engine system would be more economical during a warm upor regeneration period. If so, a low efficiency operation recommendationis generated and provided as an output from the thermal managementmodule 60. For example, the recommendation can be provided as a visualindicator on a display, such as a touch screen display, that is visibleto the vehicle operator, and/or audibly indicted over a speaker orearphones in the vehicle cockpit. Optionally, some embodiments canprovide a cost/economy benefit as output with the correspondingrecommended operation, which can be useful to the operator when decidingwhether to carry out the recommendation.

An exemplary powertrain, or engine and transmission warm up module 100determines whether down-shifting or up-shifting the transmission fromits current gear will yield a more fuel efficient solution in the longrun. By down-shifting the transmission, the engine operates at a higherspeed while producing the same amount of driveshaft power. The higherspeed may place the engine at an operating point of lower efficiency.This lower efficiency will cause more fuel to be used in producing thesame amount of power. The excess fuel energy will go toward generatingheat that will cause an increase in the system temperature. In contrast,the same concept can be used to create an up-shift event to potentiallyplace the engine at a more efficient operating condition, therebyreducing the amount of fuel energy used in generating heat. Thus, byshifting the transmission up or down, the system operating temperaturecan be controlled.

In a process of determining whether to recommend low efficiency engineoperation to the vehicle operator according to an exemplary embodiment,the following assumptions are made: instantaneous powertrain conditionscan be obtained and a constant power output P_(t) of the powertrain ismaintained; the angular velocity ω_(engine) of the engine 3 can bedetermined from a known function of the current transmission gear numberand the angular velocity of the transmission output, i.e.,ω_(engine)=F(GEAR#, ω_(trans out)); and the torque of the engineτ_(engine) can be determined form the relation:τ_(engine)=P_(t)/ω_(engine). Engine fueling is determined byinterpolating between fueling data FUEL_(cold) (ω, τ) and fueling dataFUEL_(warm) (ω, τ) from engine fueling maps at “cold” and “warmed up”conditions, respectively, as a function of engine component temperature(e.g., oil or coolant temperature). Next, an expected change intemperature (coolant, oil) per unit time is determined as a function ofcurrent ω_(engine), τ_(engine) and a first fueling value, and as afunction higher engine speed, lower torque, and a second fueling value.

To determine whether operating the powertrain a the lower efficiencymode is cost effective, an exemplary embodiment considers the rate ofchange of power/speed demand to predict a next time step power/speeddemand, P_(t+Δt)/ω_(trans out t+Δt). Given this next time value, thewarmer powertrain fuel consumption (while up-shifted) and the coolerpowertrain fuel consumption (also up-shifted) are determined. If thedifference in the fuel consumption at t+Δt is greater than the fuelconsumption to get the increased temperature, then the downsizing isworth the cost and the thermal management module 60 generates a lowefficiency engine operation recommendation, such as a down shiftoperation. Optionally a benefit estimate such as a cost or economybenefit estimate resulting from the recommended operation, can also begenerated and output by the thermal management module 60.

FIG. 4 is a signal flow diagram illustrating more details of powertrainwarns up module 100 to thermally manage the powertrain 2 in accordancewith an exemplary embodiment. As shown in FIG. 4, data indicative of atleast one current vehicle operating condition is received as an input toan ENGINE (ω, τ) calculating module 412. The operating condition dataincludes data signifying or representing current transmission out power,POWER_(t), current transmission speed or velocity out, ω_(out), currentgear number, GEAR#, and data indicating the transmission gearing set.The ENGINE (ω, τ) calculating module 412 determines the engine speed ωand engine torque τ at the current gear (GEAR#) as ENGINE (ω, τ) (NOSHIFT), and at a down shifted gear as ENGINE (ω, τ) (DN SHIFTED).

The calculated values for ENGINE (ω, τ) (NO SHIFT) and ENGINE (ω, τ) (DNSHIFTED) are provided along with data indicating or representing acurrent temperature, T_(t), of a powertrain component, such as oil orcoolant temperature, and the FUEL_(cold) (ω, τ) and FUEL_(warm) (ω, τ)data, to a table-based fuel consumption interpolator module 414 a, whichdetermines fueling, FUEL_(t) (NO SHIFT), required at the currentoperating temperature T_(t) based on speed and torque for the no shiftoperating condition, and fueling, FUEL_(t) (DN SHIFTED), required at thecurrent operating temperature T_(t) for the down shifted operatingcondition. The fueling maps can be obtained from, for example, memory ofthe ECM 6 or from storage elsewhere in the system network 15 or fromremote storage. The fueling data based on cold and warm conditions canoriginate from an engine fueling map module (not shown), which is partof the ECM or separate from, but communicably coupled with the ECM andother modules of the engine system 1. Further, such a fueling map modulecan be provided as part of the fuel consumption module 414 a.

The current operating temperature T_(t), the calculated values forENGINE (ω, τ) (NO SHIFT ENGINE (ω, τ) (DN SHIFTED), FUEL_(t) (NO SHIFT),and FUEL_(t) (DN SHIFTED) are provided to the expected enginetemperature determination module 416, which determines an expectedengine (e.g., coolant or oil) temperature at a later time increment Δtfor both the shifted and non-shifted conditions in view of the operatingcondition data including the current engine speed, torque and fueling,and for the down shifted higher engine speed, torque and fueling. Theexpected engine temperature determination module 416 provides outputT_((t+Δt)) (NO SHIFT) value as the expected powertrain temperature attime t+Δt for the non-shift (i.e. GEAR#) condition and the outputT_((t+Δt)) (DN SHIFTED) value as the expected powertrain temperature attime t+Δt for the down shifted condition.

The calculated expected temperature values are provided to a fuelconsumption interpolator module 414 b, which can be provided with orseparate from the fuel consumption interpolated module 414 a, thatdetermines the fueling, FUEL_(t+Δt) (NO SHIFT), at time t+Δt for thenon-shift (i.e. GEAR#) condition and the fueling, FUEL_((t+Δt)) (DNSHIFTED), at time t+Δt for the down shifted condition based on thetemperature value T_((t+Δt)) (NO SHIFT), the temperature valueT_((t+Δt)) (DN SHIFTED), the FUEL_(cold) (ω, τ) and FUEL_(warm) (ω, τ)data and an expected ENGINE (ω, τ)_(t+Δt). The expected ENGINE (ω,τ)_(t+Δt) is determined by an expected power/speed demand calculationmodule 418, which utilizes the current condition data POWER_(t) and theangular velocity out ω_(out t) to determine an expected power,POWER_(t+Δt), and speed, ω_(t+Δt) at a later time t+Δt, for example,based on a rate change of power/speed demand. From these calculatedvalues and the current gear, GEAR#, the expected ENGINE (ω, τ)_(t+Δt) isdetermined.

A recommendation/benefit determination module 422 is an optimizationmodule that receives the fueling FUEL_(t+Δt) (NO SHIFT) andFUEL_((t+Δt)) (DN SHIFTED) values along with the FUEL_(t) (NO SHIFT),and FUEL_(t) (DN SHIFTED) values, and a comparison is made between thewarmer powertrain fuel consumption while up-shifted and the coolerpowertrain fuel consumption, also while up shifted. Outputs of therecommendation/benefit determination module 422 include a transmissiongear shift recommendation in view of the determined expected temperaturechanges based on optimization of overall fuel economy, and optionally, abenefit estimate.

Exemplary embodiments provide for the gear shift recommendation to be adown shift command. For example, in an exemplary embodiment, therecommendation/benefit determination module 422 will generate a downshift command or suggestion only if [FUEL_(t) (DN SHIFTED)−FUEL_(t) (NOSHIFT)]<[FUEL_(t+Δt) (NO SHIFT)−[FUEL_(t+Δt) (DN SHIFTED)] and is withinsystem constraints.

The powertrain warns up module 100 can also consider information from aglobal positioning system (GPS) communicating with the thermalmanagement module 60. For example, the GPS unit 52 and road terrain androuting module 30 and other modules in the system network 15 can provideinformation on route dynamics to effect thermal management of thepowertrain in accordance with an exemplary embodiment. For instance, anexemplary embodiment of a system or method can provide for the use ofthe GPS to predict when the engine will experience higher/lower loadconditions based on the terrain of the route being traveled. Thiscapability can facilitate providing more information for look-aheaddecisions as to whether to generate a recommendation for lower efficientoperation. For example, the GPS can allow for taking advantage ofopportunities where a heat generating load on the powertrain wouldnaturally occur in the course of the route. For example, if the GPSindicates that an elevated load condition is forthcoming, such as anincreasing grade, then the control system recognizes that theanticipated higher engine speed will result in a passive increase inpowertrain temperature and forgo recommending down shift. Conversely, onlong decreasing grades, it may not be necessary to operate in aninefficient mode during warm up if duration of the lighter load is knownto long enough to allow for warming up the powertrain in a costeffective manner.

An exemplary SCR warm up/DPF regeneration module 200 determines whetherdown-shifting the transmission from its current gear, either alone or incombination with fuel dosing, will yield a more fuel efficient solutionin the long run. As explained above with respect to the powertrain warmup module, by down-shifting the transmission, the engine operates at ahigher speed while producing the same amount of driveshaft power. Thehigher speed may place the engine at a lower efficiency operating point.This lower efficiency will require more fuel to be used to produce thesame amount of power. The excess fuel energy will go toward generatingheat that will drive up the exhaust temperature. This higher exhausttemperature can be modeled along with a fuel dosing strategy todetermine an optimal solution that minimizes the overall amount of fuelconsumed in achieving a target external device temperature. Estimatingthe increased exhaust temperature can be accomplished by any methodknown to those of ordinary skill in the art, such as one of severalphysics and regression based concepts existing in the literature toestimate exhaust temperature, which can also be applied to determine theresulting increase in exhaust temperature. If down-shifting generates aninsufficient temperature increase, energy based models can be applied todetermine the excess amount of dosing fuel that is needed to achieve theremaining increase to the target temperature. For example, the exhaustgas temperature can be modeled by using the engine fueling map and theDiesel Oxidation Catalyst (DOC) outlet gas temperature can be modeled asa function of dosing fuel quantity. It is assumed through these stepsthat the DOC is at light-off temperature to ignite the dosing fuel.

To determine DOC inlet conditions, turbine temperature loss and pipeloss are evaluated. Determining the turbine and pipe losses can becarried out using calculations based on the system physics or by usingempirical models in combination with physical and/or virtual sensorsignals and data tables and/or maps.

For example, an embodiment can include physical exhaust pressure sensorsand turbine speed sensors, virtual exhaust temperature and exhaust massflow sensors, and a turbine performance map (e.g., efficiency andspeed). The engine out pressure is measured and the engine outtemperature is estimated based on engine ECM model. The turbine outpressure and operating point efficiency can be determined using theturbine performance map. Based on compressor air flow dynamics, givencorrected mass air flow and turbocharger speed, the pressure ration andturbine efficiency can be determined uniquely by two functions F₁ andF₂:

${\frac{P_{out}}{P_{in}} = {F_{1}\left( {\frac{T_{sp}}{\sqrt{T_{in}}},\frac{\overset{.}{m}\sqrt{T_{in}}}{P_{in}}} \right)}},{and}$${\eta = {F_{2}\left( {\frac{T_{sp}}{\sqrt{T_{in}}},\frac{\overset{.}{m}\sqrt{T_{in}}}{P_{in}}} \right)}},$

where T_(in) is the exhaust temperature, T_(out) is the turbine outtemperature, P_(in) is the exhaust pressure, and P_(out) is the turbineout pressure. In essence, this provides the turbine flow map. Theturbine efficiency map combined with isentropic relationship givesturbine out pressure and turbine out temperature. The turbine map usesmeasured turbine speed, inlet temperature and pressure, and mass flow todetermine outlet pressure. The unknowns can be estimated using thesenon-linear maps, and two knowns, the turbine out temperature can bedetermined using the isentropic relationship, where outlet pressure,inlet temperature, and inlet pressure is used to determine outlettemperature:

$T_{out} = {{\frac{T_{in}}{\eta}\left( {\left( \frac{P_{out}}{P_{in}} \right)^{\frac{\gamma - 1}{\gamma}} - 1} \right)} + {T_{in}.}}$

Pipe temperature loss can be determined by modeling pipe losses ΔP, ΔTto estimate true DOC inlet conditions. Incompressible flow modeling isapplicable (Mach numbers of flow<0.3). In general, Δp is a function ofgauge pressure P^(gauge), air density ρ, mass flow rate {dot over (m)},flow velocity U, the length of the flow d, and the flow area A:

${{\Delta \; p} = {F\left( {P^{gauge},\rho,U,\overset{.}{m},d,A} \right)}},{and}$${\Delta \; p} = {{K\frac{\rho}{2A^{2}}q{q}} = {{K\frac{\rho}{2}U^{2}} = {{K\frac{\rho}{2}\left( \frac{\overset{.}{m}}{\rho \; A} \right)^{2}} = {K{\frac{{\overset{.}{m}}^{2}}{2A^{2}\rho}.}}}}}$

Propose:

Δp=K ₁ P ^(gauge) +K ₂ ρU ²  (5)

Where K is a constant of proportionality, q is the flow rate, A is theflow area, U is the flow velocity, is the mass flow rate, and d is thelength of the flow. K₁, K₂ are regression fitted coefficients developedin test cell testing. P^(gauge) is gauge pressure of the pressure at theturbine outlet. Air density (ρ) is determined from the ideal gas law.Flow velocity (U) is determined from mass flow rate, pipe area and airdensity. Pressure at DOC inlet is determined from turbine outletpressure and dP empirical model. Also, using the adiabatic ideal gaslaw:

${\frac{P}{P_{t}} = \left( \frac{T}{T_{t}} \right)^{\frac{\gamma}{\gamma - 1}}},$

where P is the local static pressure, P_(t) is the stagnation pressure,T is the local static temperature, and T_(t) is the stagnationtemperature. Stagnation pressure/temperature (the totalpressure/temperature) is unchanged over fully developed streamlines(assume adiabatic behavior). Static pressure/temperature related tototal pressure/temperature (in the absence of gravity) by adding in flowvelocity, which is known. Stagnation pressure/temperature is totalpressure/temperature when flow comes to rest. Given static P (orpressure at DOC inlet), stagnation P and stagnation T use adiabaticrelationship to determine static T (or temperature at DOC inlet). Givenno losses and changes to pressure, then under adiabatic conditions thetemperature will remain unchanged as well.

SCR catalysts (sometimes referred to herein as “SCR”) currently are usedin diesel aftertreatment systems. The SCR is typically fluidly connectedto a diesel oxidation catalyst (DOC) and positioned downstream of theDOC with a diesel particulate filter (DPF) provided between the SCR andDOC. The SCR requires a reductant dosing system, such as a dieselemissions fluid (DEF) dosing system, which is provided upstream of theSCR to inject a reductant such as anhydrous NH₃ aqueous NH₃, or mostoften a precursor that is convertible to NH₃ such as urea ammonia orurea, into the exhaust flow. The reductant dosing system can include adoser, a decomposition reactor, and a mixer. The reductant is adsorbedonto a catalyst surface in the SCR where it is used to convert the NOxemissions in the exhaust gas flow to nitrogen and water, and in the caseof urea, also into carbon dioxide.

FIG. 5 shows an exemplary embodiment of an exhaust aftertreatment system500 attached to an exhaust gas conduit segment 510 b downstream of aturbine 520 of a turbocharger. The aftertreatment system 500 includes aDOC 530 in the exhaust gas path downstream of the turbine 520, a DPF 540in the exhaust gas path downstream of the DOC 530, and an SCR 550 in anexhaust gas path downstream of the DPF 530. A hydrocarbon (HC) doser 560is provided in the exhaust gas conduit segment 510 b between the turbine520 and the DOC 530 to inject fuel into the exhaust gas flow. Anexemplary temperature distribution is also depicted on the segments 510a-510 d of the exhaust gas conduit. As can be seen, the exhaust gastemperature drops from 475° C. in the exhaust gas conduit segment 510 aat the inlet of turbine 420 to 350° C. in the exhaust gas conduitsegment 510 b at the inlet of the DOC 530, increases across the DOC 530from 350° C. to 525° C. at the exhaust gas conduit segment 510 c, andthen increases to 550° C. in the exhaust gas conduit segment 510 d atthe outlet of the DPF 540.

To determine the mass flow rate of fuel, an energy balance equationacross the DOC 530 is utilized:

Energy_(In)+Energy_(Gen)=Energy_(Out)+Energy_(Lost)+Energy_(Stored).

The two right terms on the right of the above equation are negligible,leading to:

({dot over (m)} _(exh) +{dot over (m)} _(fuel))*Cp _(in) *T _(in) +m_(fuel) *LHV _(fuel)=({dot over (m)} _(exh) +{dot over (m)} _(fuel))*Cp_(trgt) *T _(trgt),

and the mass flow of fuel associated with energy is negligible, leadingto:

${\overset{.}{m}}_{fuel} = {\frac{{Nominal\_ Gain}*{\overset{.}{m}}_{exh}*\left( {{C_{p}*T_{trgt}} - {{Cp}_{in}*T_{in}}} \right)}{{LHV}_{fuel} - {{Cp}_{trgt}*T_{trgt}}}.}$

In a process of determining whether to recommend low efficiency engineoperation to the vehicle operator according to an exemplary embodiment,the following assumptions are made: instantaneous powertrain conditionscan be obtained and a constant power output P_(t) of the powertrain ismaintained; the angular velocity ω_(engine) of the engine 3 can bedetermined from a known function of the current transmission gear numberand the angular velocity of the transmission output,(ω_(engine)=F(GEAR#, ω_(trans out)); the torque of the engine τ_(engine)can be determined form the relation: τ_(engine)=P_(t)/ω_(engine); andthe DOC 530 is at a light-off temperature. Given the current DPFtemperature and the target temperature, the required DOC ΔT can bedetermined. This can be achieved by in-cylinder or exhaust conduitdosing of fuel that lights off in the DOC 530, running the engineinefficiently, for example, at a high speed, or a combination of fueldosing and inefficient engine operation. The exhaust conditions can bemodeled using the engine fueling map for warm operation, FUEL_(warm)(ω,τ), AND the exhaust temperature can be modeled as a function of (ω, τ).The outlet gas temperature of the DOC 530 can be modeled as a functionof doping fuel quantity.

Given the desired engine out power, the following quantities aredetermined: X=total fueling due to down shifting and meeting theremaining temperature target with dosing; and Y=total fueling due tomeeting the whole temperature target with dosing. The thermal managementmodule 60 generates a low efficiency engine operation recommendation,such as a down shift operation and provided to the operator interfacemodule 40 if it is determined that X is less than Y.

FIG. 6 is a signal flow diagram illustrating more details of an SCR warmup/DPF regeneration module 200 to thermally manage the exhaustaftertreatment system 5 in accordance with an exemplary embodiment. Asshown in FIG. 6, data indicative of at least one current vehicleoperating condition is received as an input to an ENGINE (ω, τ)calculating module 612. The operating condition data includes datasignifying or representing current transmission out power, POWER_(t),current transmission speed or velocity out, ω_(out), current gearnumber, GEAR#, and data indicating the transmission gearing set. TheENGINE (ω, τ) calculating module 612 determines the engine speed ω andengine torque τ at the current gear (GEAR#) as ENGINE (ω, τ) (NO SHIFT),and at a down shifted gear as ENGINE (ω, τ) (DN SHIFTED).

The calculated values for Engine (ω, τ) (NO SHIFT) and ENGINE (ω, τ) (DNSHIFTED) are provided along with data FUEL_(warm)(ω, τ) from enginefueling maps at “warmed up” conditions to a table-based fuel consumptioninterpreter module 614, which determines fueling, FUEL_(t) (NO SHIFT),required based on speed and torque for the no shift operating conditionand fueling, FUEL_(t) (DN SHIFTED), required for the down shiftedoperating condition. The fueling maps can be obtained from, for example,memory of the ECM 6 or from storage elsewhere in the system network 15or from remote storage. The fueling data based on warm conditions canoriginate from an engine fueling map module (not shown), which is partof the ECM or separate from, but communicably coupled with the ECM andother modules of the engine system 1.

The calculated values for Engine (ω, τ) (NO SHIFT), Engine (ω, τ) (DNSHIFTED), FUEL_(t) (NO SHIFT), and FUEL_(t) (DN SHIFTED) are provided tothe expected exhaust temperature determination module 616, whichdetermines an expected exhaust temperature at a later time increment Δtfor both the shifted and non-shifted conditions in view of the operatingcondition data and the fueling maps, for example, utilizing one ofseveral known physics and known regression based concepts existing inthe literature. The expected exhaust temperature determination module616 provides output T_((t+Δt)) (NO SHIFT) value as the expected exhausttemperature at time t+Δt for the non-shift (i.e. GEAR#) condition andthe output T_((t+Δt)) (DN SHIFTED) value as the expected exhausttemperature at time t+Δt for the down shifted condition.

The calculated expected temperature values are provided to a dosing fuelcalculator module 618 that utilizes an energy-based model. Also providedto the dosing fuel calculator module 618 is a temperature targetT_(target), engine speed ω (DN SHIFTED) related to the shiftedcondition, engine speed ω (NO SHIFT) related to the non-shiftedcondition to help compute the exhaust flow, as inputs to determine thedosing fuel required to reach the target temperature T_(target). Otherinputs can be provided as well to further refine the physics model. Thedosing fuel calculator module 618 outputs a value of dosing fuelrequired for meeting T_(target) in the down shifted operating conditionFUEL_(t) (DN SHIFTED DOSING) and a value of dosing fuel required formeeting T_(target) in the non-shifted operating condition FUEL_(t) (NOSHIFT DOSING). The target temperature data T_(target) can originate froma target temperature module (not shown), which is part of the ECM orseparate from, but communicably coupled with the ECM and other modulesof the engine system 1.

The fueling values FUEL_(t) (DN SHIFTED DOSING) and FUEL_(t) (NO SHIFTDOSING) are provided along with the fueling values FUEL_(t)(DN SHIFTED)and FUEL_(t)(NO SHIFT) determined by the fuel consumption interpretermodule 614 to a recommendation/benefit determination module 620, where acomparison is made between fueling required to reach T_(target) usingdown-shifting plus, if required, fueling needed in meeting the remainingtemperature target with dosing, and/against total fueling due to meetingthe temperature target with dosing alone. Exemplary embodiments providefor the dosing to occur in-cylinder and to light-off in the DOC,although dosing can be provided to the exhaust flow downstream of theengine in another embodiment. Outputs of the recommendation/benefitdetermination module 620 include a transmission gear shiftrecommendation in view of the determined expected temperature changesbased on optimization of overall fuel economy, and a benefit estimate.It is to be appreciated that the functions performed byrecommendation/benefit determination module 620 can be carried out bymore than one module, or submodules of the recommendation/benefitdetermination module 620. For example, the comparison between the aboverequired fueling can be performed by a comparison module, and thetransmission gear shift recommendation can be contained in aoptimization module.

Additionally, the expected exhaust temperature determination module 816can determine more than two expected temperatures. For example, a firstexpected exhaust temperature can be determined based on a transmissiondown shift and higher engine speed in view of the operating conditiondata and the fueling maps, a second expected exhaust temperature can bedetermined based on a transmission down shift and higher engine speedcoupled with late post fuel injection, and a third expected exhausttemperature can be determined based on late post fuel injection andnon-shifted transmission. The recommended benefit determination module820 can compare the first, second and third expected exhausttemperatures against the target temperature and provide a transmissiongear shift recommendation in view of the compared expected exhausttemperatures based on an optimization of overall fuel economy. As above,the functions of comparing and recommendation can be carried out usingdifferent comparison and optimization modules.

Exemplary embodiments provide for the gear shift recommendation to be adown shift command. For example, in an exemplary embodiment, therecommendation/benefit determination module 620 will generate a downshift command or suggestion only if [FUEL_(t)(DN SHIFTED)+FUEL_(t)(DNSHIFTED DOSING)]<[FUEL_(t)(NO SHIFT)+FUEL_(t) (NO SHIFT DOSING)] and iswithin system constraints.

FIG. 7 is a signal flow diagram of an exemplary process 700 illustratingemployment of a global positioning system (GPS) of the thermalmanagement module 60, which can include the GPS unit 52 and road terrainand routing module 30 and other modules in the system network 15, toprovide information on route dynamics in utilizing the vehicleengine/transmission system to effect aftertreatment system thermalmanagement in accordance with an exemplary embodiment. Exemplaryembodiments of the systems and methods provide for the use of the GPS topredict when the engine will experience higher/lower load conditions.This capability will facilitate expedient control of active DPFregeneration by taking advantage of opportunities for passiveregeneration or thermal management of the DPF subsystem. For example, ifthe GPS indicates that an elevated load condition is forthcoming, suchas an increasing grade, then the control system recognizes that theanticipated higher engine speed will result in a passive increase inexhaust temperature and can then deliberately inhibit activeregeneration. Suppressing active regeneration will result in a savingsof fuel consumed.

Use of the GPS to predict higher/lower engine load conditions can alsoreduce the need for full active regeneration, as typically occurs inurban driving conditions. In the exemplary process 700, a current sootis monitored in process 710. A look-ahead window, which can be based ontime or distance, is activated or employed in process 720 to identifyanticipated vehicle load changes. For example, in an embodiment, thelook-ahead window can be activated after the soot load in the DPFexceeds a given threshold. In process 730, the GPS data, for example,data related elevation/speed limit, provides a profile for thelook-ahead window. In process 740, the exhaust temperature is determinedover the look-ahead window based on the profile provided by the GPSdata. Assuming optimal transmission matching (or given a transmissionshifting map), the vehicle load can be translated into an engine load.Given an exhaust temperature versus engine load map, as well as anexhaust particulate matter (PM) map, an estimate can be made of theexpected DPF soot loading over the look-ahead window in process 750. Inprocess 760, the cost of passive and active increase of DPF temperaturefor regeneration is assessed over the look-ahead window, and process 770identifies a lowest cost combination of passive and active regenerationat all unique start points in the look-ahead window. Process 780triggers a passive and active regeneration combination at the lowest oroptimal of the identified cost points, and process 790 repeats the aboveprocesses for the next look-ahead window.

Also, it is to be appreciated that the thermal management module 60 candetermine when the DPF will require regeneration at any time and use theGPS data to determine whether there is a high loading opportunity in thevicinity of the required regeneration event. If such an opportunity isidentified, then it can be exploited to supplement regeneration of theDPF, with active regeneration as needed.

An exemplary DOC warm up module 300 determines whether down-shifting thetransmission from its current gear, either alone or in combination withlate post fuel injection, will yield a more fuel efficient solution inthe long run. As described above, by down-shifting the transmission, theengine operates at a higher speed while producing the same amount ofdriveshaft power. The higher speed may place the engine at a lowerefficiency operating point, which will require more fuel to be used toproduce the same amount of power. The excess fuel energy will go towardgenerating heat that will drive up the exhaust temperature. This higherexhaust temperature can be modeled along with a late post fuelingstrategy to determine an optimal solution that minimizes the overallamount of fuel consumed in achieving a target external devicetemperature. Estimating the increased exhaust temperature can beaccomplished by any method known to those of ordinary skill in the art,such as one of several physics and regression based concepts existing inthe literature to estimate exhaust temperature, which can also beapplied to determine the resulting increase in exhaust temperature.Turbine and pipe loss models can be applied to determine the temperatureloss from the engine exhaust to the DOC inlet, and are described abovewith respect to the SCR warm up/DPF regeneration module 200. Ifdown-shifting generates an insufficient temperature increase, exemplaryembodiments provide for energy based models to be applied to determinethe excess amount of late post fuel dosing fuel that is needed to theremaining increase to the target temperature. For example, the exhaustgas temperature can be modeled by using the engine fueling map, and theDiesel Oxidation Catalyst (DOC) outlet gas temperature can be modeled asa function of late post injection dosing fuel quantity.

In a process of determining whether recommend low efficiency engineoperation to the vehicle operator according to an exemplary embodiment,the following assumptions are made; instantaneous powertrain conditionscan be obtained and a constant power output P_(t) of the powertrain ismaintained; the angular velocity ω_(engine) of the engine 3 can bedetermined from a known function of the current transmission gear numberand the angular velocity of the transmission output, i.e.,ω_(engine)=F(GEAR#, ω_(trans out)); the torque of the engine τ_(engine)can be determined form the relation: τ_(engine)=P_(t)/ω_(engine); andthe DOC 530 is at a light-off temperature. Given the current DPFtemperature and the target temperature, the required DOC ΔT can bedetermined. This can be achieved by in-cylinder late posts that generateheat to increase the exhaust temperatures, running the engineinefficiently, for example, at a high speed, or a combination of lateposts and inefficient engine operation. The exhaust conditions can bemodeled using the engine fueling map for warm operation, FUEL_(warm)(ω,τ), and the exhaust gas temperature can be modeled as a function of (ω,τ). The DOC inlet gas temperature can be modeled as a function of latpost injection fuel quantity.

Given the desired engine out power, the following quantities aredetermined: X=total fueling due to down shifting and meeting theremaining temperature target with lat post for heat; and Y=total fuelingdue to meeting the whole temperature target with late post for heat. Thethermal management module 60 generates a low efficiency engine operationrecommendation, such as a down shift operation and provided to theoperator interface module 40 if it is determined that X is less than Y.Further, it is assumed that other heat generating devices, such asmaneuvering a VGT, the use of intake air throttles, EGR cooler bypasses,etc. are all assumed to be unchanged between the scenarios X and Y.

FIG. 8 is a diagram illustrating more details of an exemplary DOC warmup module 800 that thermally manages the exhaust aftertreatment system 5to bring the DOC to light-off temperature in accordance with anexemplary embodiment. As shown in FIG. 8, data indicative of at leastone current vehicle operating condition is received as an input to anENGINE (ω, τ) calculating module 812. The operating condition dataincludes data signifying or representing current transmission out power,POWER_(t), and current transmission speed or velocity out, ω_(out),current gear number, GEAR#, and data indicating the transmission gearingset, GEAR SET. The ENGINE (ω, τ) calculating module 812 determines theengine speed ω and engine torque τ at the current gear (GEAR#) as ENGINE(ω, τ) (NO SHIFT) and at a down shifted gear as ENGINE (ω, τ) (DNSHIFTED).

The calculated values for ENGINE (ω, τ) (NO SHIFT) and ENGINE (ω, τ) (DNSHIFTED) are provided along with data FUEL_(warm) (ω, τ) from enginefueling maps at “warmed up” conditions to a table-based fuel consumptioninterpreter module 814, which determines fueling, FUEL_(t) (NO SHIFT),required based on speed and torque for the no shift operating conditionand fueling, FUEL_(t) (DN SHIFTED), required for the down shiftedoperating condition. The fueling maps can be obtained from, for example,memory of the ECM 6 or from storage elsewhere in the system network 15or from remote storage. The fueling data based on warm conditions canoriginate from an engine fueling map module (not shown), which is partof the ECM or separate from, but communicably coupled with the ECM andother modules of the engine system 1.

The calculated values for ENGINE (ω, τ) (NO SHIFT), ENGINE (ω, τ) (DNSHIFTED), FUEL_(t) (NO SHIFT), and FUEL_(t) (DN SHIFTED) are provided tothe expected exhaust temperature determination module 816, whichdetermines an expected exhaust temperature at a later time increment Δtfor both the shifted and non-shifted conditions in view of the operatingcondition data and the fueling maps, for example, utilizing one ofseveral known physics and known regression based concepts existing inthe literature. The expected exhaust temperature determination module816 provides output T_((t+Δt)) (NO SHIFT) value as the expected exhausttemperature at time t+Δt for the non-shift (i.e. GEAR#) condition andthe output T_((t+Δt)) (DN SHIFTED) value as the expected exhausttemperature at time t+Δt for the down shifted condition.

The calculated expected temperature values are provided to a late postfuel calculator module 818 that utilizes an energy-based model and caninclude turbine and pipe losses, as described above with respect to theSCR warm up/DPF regeneration module 200. Also provided to the dosingfuel calculator module 818 is a temperature target T_(target), enginespeed ω (DN SHIFTED) related to the shifted condition, engine speed ω(NO SHIFT) related to the non-shifted condition to help compute theexhaust flow, as inputs to determine the dosing fuel required to reachthe target temperature T_(target). Other inputs can be provided as wellto further refine the physics model. The late post fuel calculatormodule 818 outputs a value of late post fuel required for meetingT_(target) in the down shifted operating condition FUEL_(t) (DN SHIFTEDLATE POST) and a value of lat post fuel required for meeting T_(target)in the non-shifted operating condition FUEL_(t) (NO SHIFT LATE POST).The target temperature data T_(target) can originate from a targettemperature module (not shown), which is part of the ECM or separatefrom, but communicably coupled with the ECM and other modules of theengine system 1.

The fueling values Fuel_(t) (DN SHIFTED LATE POST) and FUEL_(t) (NOSHIFT LATE POST) are provided along with the fueling values FUEL_(t) (DNSHIFTED) and FUEL_(t)(NO SHIFT) determined by the fuel consumptioninterpreter module 814 to a recommendation/benefit determination module820, where a comparison is made between fueling required to reachT_(target) using down-shifting plus, if required, fueling needed inmeeting the remaining temperature target with dosing, and/against totalfueling due to meeting the temperature target with dosing alone.Exemplary embodiments provide for the dosing to occur in-cylinder and tolight-off in the DOC. Outputs of the recommendation/benefitdetermination module 820 include a transmission gear shiftrecommendation in view of the determined expected temperature changesbased on optimization of overall fuel economy, and a benefit estimate.It is to be appreciated that the functions performed byrecommendation/benefit determination module 820 can be carried out bymore than one module, or submodules of the recommendation/benefitdetermination module 820. For example, the comparison between first andsecond exhaust temperatures relative to the target temperature can becontained and performed by a comparison module, and the transmissiongear shift recommendation can be contained and performed in anoptimization module.

Additionally, the expected exhaust temperature determination module 816can determine more than two expected temperatures. For example, a firstexpected exhaust temperature can be determined based on a transmissiondown shift and higher engine speed in view of the operating conditiondata and the fueling maps, a second expected exhaust temperature can bedetermined based on a transmission down shift and higher engine speedcoupled with fuel dosing, and a third expected exhaust temperature canbe determined based on fuel dosing and non-shifted transmission. Therecommended benefit determination module 820 can compare the first,second and third expected exhaust temperatures against the targettemperature and provide a transmission gear shift recommendation in viewof the compared expected exhaust temperatures based on an optimizationof overall fuel economy. As above, the comparing and recommendation canbe carried out using different modules.

Exemplary embodiments provide for the gear shift recommendation to be adown shift command. For example, in an exemplary embodiment, therecommendation/benefit determination module 820 will generate a downshift command or suggestion only if [FUEL_(t)(DN SHIFTED)+FUEL_(t) (DNSHIFTED LATE POST)]<[FUEL_(t)(NO SHIFT)+FUEL_(t) (NO SHIFT LATE POST)]and is within system constraints.

Many aspects of this disclosure are described in terms of sequences ofactions to be performed by elements of a controller, control moduleand/or a network system, which can be a computer system or otherhardware capable of executing programmed instructions. These elementscan be embodied in a controller of an engines system, such as the ECM 5,or in a controller separate from, and communicating with the ECM 5. Inan embodiment, the controller and/or ECM can be part of a CAN in whichthe controller, sensor, actuators communicate via digital CAN messages.It will be recognized that in each of the embodiments, the variousactions could be performed by specialized circuits (e.g., discrete logicgates interconnected to perform a specialized function), by programinstructions, such as program modules, being executed by one or moreprocessors (e.g., a central processing unit (CPU) or microprocessor), orby a combination of both, all of which can be implemented in a hardwareand/or software of the ECM and/or other controller or pluralcontrollers. For example, the engine parameter/operating conditionsmodule 20 can be implemented as separate modules for the engineparameters and current operating conditions. Logic of embodimentsconsistent with the disclosure can be implemented with any type ofappropriate hardware and/or software, with portions residing in the formof computer readable storage medium with a control algorithm recordedthereon such as the executable logic and instructions disclosed herein,and can be programmed, for example, to include one or more singular ormulti-dimensional engine and turbine look-up tables and/or calibrationparameters. The computer readable medium can comprise tangible forms ofmedia, for example, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (e.g., EPROM, EEPROM,or Flash memory), an optical fiber, and a portable compact discread-only memory (CD-ROM), or any other solid-state, magnetic, and/oroptical disk medium capable of storing information. Thus, variousaspects can be embodied in many different forms, and all such forms arecontemplated to be consistent with this disclosure.

Although a limited number of exemplary embodiments is described herein,one of ordinary skill in the art will readily recognize that there couldbe variations to any of these embodiments and those variations would bewithin the scope of the disclosure.

1. A method to determine a transmission gear shift recommendation basedon optimization of overall fuel economy, the method comprising:receiving data indicative of at least one current vehicle operatingcondition, said operating condition data including data representing orsignifying at least one of transmission out power and speed, currentgear number, transmission gearing set, current engine temperature,current engine speed, current engine torque, and fueling; receiving datafrom engine fueling maps based on cold and warm-up conditions;determining an expected temperature change based on a transmission downshift and higher engine speed in view of said operating condition dataand said fueling maps; determining an expected temperature change basedon a transmission up shift and lower engine speed in view of saidoperating condition data and said fueling maps; and determining atransmission gear shift recommendation in view of said determinedexpected temperature changes based on optimization of overall fueleconomy.
 2. The method of claim 1, wherein the gear shift recommendationis a down shift command.
 3. A system adapted to determine a transmissiongear shift recommendation based on optimization of overall fuel economy,comprising: a vehicle operating condition module including dataindicative of at least one current vehicle operating condition, saidoperating condition data including data representing or signifying atleast one of transmission out power and speed, current gear number,transmission gearing set, current engine temperature, current enginespeed, current engine torque, and fueling; an engine fueling map moduleincluding data from engine fueling maps based on cold and warm-upconditions; an expected temperature change module including data basedon a transmission down shift and higher engine speed in view of saidoperating condition data and said fueling maps, and including data basedon transmission up shift and lower engine speed in view of saidoperating condition data and said fueling maps; and an optimizationmodule containing a transmission gear shift recommendation in view ofsaid determined expected temperature changes based on optimization ofoverall fuel economy.
 4. A method of managing vehicleengine/transmission systems to assist in thermal management of an engineexhaust aftertreatment system, the method comprising: receiving dataindicative of at least one current vehicle operating condition, saidoperating condition data including data signifying at least one oftransmission out power and speed, current gear number, transmissiongearing set, current engine temperature, current engine speed, currentengine torque, and fueling; receiving data from engine fueling mapsbased on warm-up conditions; receiving a target temperature; determininga first expected exhaust temperature based on a transmission down shiftand higher engine speed in view of said operating condition data andsaid fueling maps; determining a second expected exhaust temperaturebased on a transmission down shift and higher engine speed coupled withfuel dosing; determining a third expected exhaust temperature based onfuel dosing and non-shifted transmission; comparing said first, secondand third expected exhaust temperatures against said target temperature;and providing a transmission gear shift recommendation in view of thecompared expected exhaust temperatures based on an optimization ofoverall fuel economy.
 5. The method of claim 4 wherein the transmissiongear shift recommendation is a down shift command.
 6. The method ofclaim 4, wherein a Global Positioning System (GPS) provides informationon route dynamics in utilizing the vehicle engine/transmission system toexploit passive increases in exhaust temperature in the aftertreatmentsystem thermal management.
 7. A system adapted to manage vehicleengine/transmission systems to assist in thermal management of an engineexhaust aftertreatment system, comprising: a vehicle operating conditionmodule including data indicative of at least one current vehicleoperating condition, said operating condition data including datasignifying at least one of transmission out power and speed, currentgear number, transmission gearing set, current engine temperature,current engine speed, current engine torque, and fueling; an enginefueling map module including data from engine fueling maps based onwarm-up conditions; a target temperature module including a targettemperature; an expected exhaust temperature module containing a firstexpected exhaust temperature based on a transmission down shift andhigher engine speed in view of said operating condition data and saidfueling maps, a second expected exhaust temperature based on atransmission down shift and higher engine speed coupled with fueldosing, and a third expected exhaust temperature based on fuel dosingand non-shifted transmission; a comparison module containing acomparison of said first, second and third expected exhaust temperaturesrelative to said target temperature; and an optimization modulecontaining a transmission gear shift recommendation in view of saidcomparison of said expected exhaust temperatures, said recommendationbeing based on an optimization of overall fuel economy.
 8. The system ofclaim 7, further comprising a Global Positioning System (GPS) module toprovide information on route dynamics in utilizing the vehicleengine/transmission system to exploit passive increases in exhausttemperature in the aftertreatment system thermal management.
 9. A methodof managing vehicle engine/transmission systems to assist in thermalmanagement of an engine aftertreatment DOC warm-up system, the methodcomprising: receiving data indicative of at least one current vehicleoperating condition, said operating condition data including datasignifying at least one of transmission out power and speed, currentgear number, transmission gearing set, current engine temperature,current engine speed, current engine torque, and fueling; receiving datafrom engine fueling maps based on warm-up conditions; receiving a targettemperature related to DOC light-off; determining a first expectedexhaust temperature based on a transmission down shift and higher enginespeed in view of said operating condition data and said fueling maps;determining a second expected exhaust temperature based on atransmission down shift and higher engine speed coupled with late postfuel injection; determining a third expected exhaust temperature basedon late post fuel injection and non-shifted transmission; comparing saidfirst, second and third expected exhaust temperatures against saidtarget temperature; and providing a transmission gear shiftrecommendation in view of the compared expected exhaust temperaturesbased on an optimization of overall fuel economy.
 10. The method ofclaim 9, wherein the transmission gear shift recommendation is a downshift command.
 11. The method of claim 9, wherein a Global PositioningSystem (GPS) provides information on route dynamics in utilizing thevehicle engine/transmission system to exploit passive increases inexhaust temperature in DOC system thermal management.
 12. A systemadapted to manage vehicle engine/transmission systems to assist inthermal management of an engine aftertreatment DOC warm-up system,comprising: a vehicle operating condition module including dataindicative of at least one current vehicle operating condition, saidoperating condition data including data signifying at least one oftransmission out power and speed, current gear number, transmissiongearing set, current engine temperature, current engine speed, currentengine torque, and fueling; an engine fueling map module including datafrom engine fueling maps based on warm-up conditions; a targettemperature module including a target temperature related to DOClight-off; an expected exhaust temperature module containing a firstexpected exhaust temperature based on a transmission down shift andhigher engine speed in view of said operating condition data and saidfueling maps, a second expected exhaust temperature based on atransmission down shift and higher engine speed coupled with late postfuel injection, and a third expected exhaust temperature based on latepost fuel injection and non-shifted transmission; a comparison modulecontaining a comparison of said first, second and third expected exhausttemperatures relative to said target temperature; and an optimizationmodule containing a transmission gear shift recommendation in view ofsaid comparison of said expected exhaust temperatures, saidrecommendation being based on an optimization of overall fuel economy.13. The system of claim 12, further comprising a Global PositioningSystem (GPS) module to provide information on route dynamics inutilizing the vehicle engine/transmission system to exploit passiveincreases in exhaust temperature in DOC system thermal management.